Method and apparatus for determining flowability of coating materials



April 28', 1936. v w, YEAGER 2,038,622

METHOD ANDAPPARATUS FOR DETERMINING FLOWABILITY OF COATING MATERIALS Filed July 6, 1933 2 I1 i52 Fi Z INVENTOR Han/T W leay er BY 7w ATTORNEY Patented Apr. 1936 PATENT OFFICE.

METHOD AND APPARATUS FOR DETERMIN- lNG FLOWABILITY OF COATING MATE- RIALS Frank William Yeager, Grantwood, N. J assignor to The Barrett Company, New York, N. Y., a corporation of New Jersey .A'pplication July 6, 1933, SerialNo.'679,187

. This invention relates lac-apparatus and methods for measuring flowability and more particularly for determining the flow characteristics of fluid bituminous coating materials. By the term 5 flowability is meant the relation between the application temperature of a coating material and the thickness of the resultant coating on a given surface at apredetermined temperature, i. e. in the case of the coating of metal pipe, the

relation between the temperature of the coating material and the thickness of the. coating formed on the pipe.

One object of the invention is to provide an apparatus and method for accurately measuring is the flowability of liquids which form solid coatsuch liquids should be poured onto pipes or other surfaces to produce protective coatings of the desired thickness. In other words, this inven tion permits the determination of the application temperature of the coating material to yield a desired thickness of coating. Other objects and advantages will appear from the-following detailed description of this invention.

At the present time bituminous coating materials are extensively used for protecting exposed surfaces against corrosion and deterioration. For

instance, in the laying of pipe lines, especially underground lines, it is customary to apply a protective coating of bituminous material to the pipe to prevent subsequent soil corrosion. This coating operation is often carried out by pouring coating material in a heated and fluid condition directly onto the top of a stationary pipe and allowing the coating material to flow down over both sides.

pipe and is applied to this portion of the pipe surface by moving the sling back and forth;

Another method of coating pipes in the field involves supporting a pipe section on a rig, rotating the section on the rig, and pouring heated coating material ontothe top of the rotating pipe.

Generally speaking the higher the temperature at which the coating material is applied, the more fluid will be the coating material and the thinner will be the resultant coating on the pipe. If the application temperature is too high, the coating on the pipe will be too thin to efiectively withstand corrosion and soil stress. If, on the other hand, the application temperature is too low, the coating on the pipe will be thicker than necessary thereby resulting in waste of coating material.

Excess coating material is caught in a sling held against thelower portion of the 9. Claims. (01.- 73-51) For each coating material there is an optimum temperature at which it should be used. This temperature .depends not only upon the particular coating material used but also upon atmospheric conditions, the temperature of the pipe onto 5 which the coating material is applied, andother variable factors. v

Prior to this invention no satisfactory apparatus or procedure had been developed for determining the temperature at which the coating ma- 10 terial should be used to obtain a protective coat of the proper thickness.

It is, of course, well known-to determine the softening points or melting points of bituminous and other coating materials, as for example by the so-called ring and ball methods Softening point and melting point determinations, however, are not a true measure or indication of the flowability of coating materials. I havefound that the application of materials having the same ring and 20 ball softening point to pipes in the field, the temperature of the coating material being substan tially the same, often gave widely divergent results, i. e., the thickness of the coating varied materially. 25

Similarly, a study of the absolute viscosity of a coating material yields only partial useful data. The reason for this is that the flowability, ,i. e., the relation between application temperature and thickness ofcoating, is actually the resultant 30 of a series of complicated factors. These factors include the absolute viscosity of the coating material over the range of temperature through which it cools in flowing over the pipe, the rate of cooling as affected by pipe and atmospheric temperatures, volume of coating material applied, pipe diameter, andpossibly other more obscure variables. I

I have devised an apparatus and method for 40 accurately determining the flowability of coating materials. In accordance with my invention, a measured quantity of'coating material,- at a. known'temperature, is discharged from a moving container onto the top of a stationary pipe s'ec- 45 tion.. 'Means are provided for regulating the temperaturesof the coating material/and the pipe section on which the coating material is poured. After the coating on the pipe has set, it is stripped off and itsthicknessmeasured. By 50 running tests with the same coatingmaterial' at a number of application temperatures and determining the average thiclmess of coating produced at each temperature, it is possible to interpolate the results and determine the temperature 56 at which the coating material should be poured to produce a coating of the desired thickness.

For a better understanding of the invention reference should be made to the accompanying drawing'wherein is shown by way of illustration a preferred embodiment of the invention and in which;

Fig. 1 is a side elevation of the apparatus embodying this invention and showing the position of the container at the commencement of the operations;

Fig. 2 is a plan view of the apparatus of Fig. l with the cover of the container partly broken away to show the discharge orifice at the bottom of the container;

Fig. 3 is a side elevation of the apparatus showing the position of the container at the completion of the coating operation; and

Fig. 4 is a small scale end elevation showing the arrangement of the spring-actuated plate for closing the orifice in the container.

Referring to the drawing with particular reference to Fig. 1, numeral l indicates a base on which is supported a half section of pipe 3, which may be a half section of a 10 inchnpipe. Bottom 5 and end walls 6 and 1', which may be sheet steel, are welded or otherwise joined to the half section of the pipe to form a hollow liquid-tight semi-cylindrical housing 8. A supply pipe 19, equipped with a filling funnel l 1, leads into the end wall 6 near the-top of the semi-cylindrical housing and provides an inlet means for introducing liquid into the housing. A drain pipe l3 provided with valve I4 is connected to an outlet in end wall 6 near the bottom of the housing.

Passing through the-opposite end wall 1 is a shaft l6 having a crank H. A series of paddles or blades l8 are joined to that portion of the shaft which is enclosed within the semi-cylindrical housing. As the crank I1 is turned, the shaft and paddles will .-rotate and agitate the liquid contained in the housing. Thermometer 19, passing through end wall I, is provided for indicating the temperature within the housing.

Vertical standards'2l, rigidly attached to the base of the apparatus, support two horizontal guide bars 23 running above the pipe and extending longitudinally on each side thereof. Numeral 25 indicates in general a container for holding the bituminous composition to be tested. Side arms 21 attached to the container are provided at their ends with members 28 adapted to rest on the guide bars and support the container thereon. As shown in the drawing, these members may be semi-cylindrical in shape and have an inside diameter somewhat larger than the diameter of the guide bars over which they fit so that they can readily be moved therealong.

Container 25 comprises a hollow pot 30, the lower portion of which is cone-shaped, having the apex or narrow end lowermost.- The top of the pot is adapted to be closed by a readily removable cover 3| having a thermometer 33 inserted therethrough and provided also with a vent hole 35. The bottom or apex of the pot is truncated to provide an orifice 36. Pot 3D is sur- .rounded, except at the bottom and top, by a cythe walls of the shell, admit air to sustain com- This burner is conbustion of the gas and provide an outlet for the products of combustion.

A rotatable shaft 43 provided with a crank 44 is mounted in brackets 45 fixed to the vertical standards 2| at the right end of the apparatus. Grooved pulley 41 is keyed or otherwise firmly fixed on the shaft 43 at a point approximately in line with the center line of the container and the longitudinal axis of the pipe section. A wire or chain 48 is attached at one end to the pulley and at the other end to the shell of the container 25. As the crank 44 is rotated, the pulley will revolve and wind the wire around its periphery thereby moving the container over the pipe sections from left to right.

A suitable closure plate assembly for preventing flow of coating material from pot 30, when the container 25 is in the position shown in Fig. 1, is indicated by reference numeral 50. In this assembly are two short vertical posts 52 welded or otherwise secured to the pipe section a short distance from end wall 6. A fiat horizontal plate 53, provided near its ends with holes through which the posts pass, extends transversely across and above the pipe section. The tops of these posts are provided with heads 55 which are larger in diameter than the holes in plate 53 through which the posts pass. fit around the 'posts and press against the bottom of thecplate and the surface of the pipe section.

-These springs tend to push the plate vertically upward, heads 55 on the posts limiting the possible movement ofthe plate and preventing it from being pushed off.

In preparing the apparatus for determining the fiowability, thesurface of the pipe section is first carefully cleaned to remove any dirt or coating material. After being cleaned, the pipe surface is slightly oiled to prevent adhesion of the coating material and permit the ready removal of the coating material after solidifying and setting.

At the start of the operations the container is pushed to the extreme left position as shown in Fig. 1 so that the orifice in the bottom of the 'pot will be positioned directly over spring actuated plate 53. The bottom of the pot is slightly lower than the uppermost position of the spring actuated plate so that, in order to place the container in the initial position, the plate must be depressed somewhat against the action of springs 56. The pressure of the spring actuated plate against the bottom of the pot effectively closes the orifice and prevents the discharge of coating material therefrom.

- Water or brine at the proper temperature is introduced into the semi-cylindrical housing 8 through funnel II and supply line H]. By rotating crank ll, the liquid in the housing is kept agitated and the pipe section brought to a. uniform temperature. Under ordinary conditions it is desirable to have the liquid in the housing at such a temperature that the pipe section will assume and maintain a temperature of about 77 F. However, to simulate conditions which would exist if the pipe were being coated under a hot sun, t. e liquid may be heated sufiiciently to produce a pipe temperature of about 150 F. Similarly, toobtain conditions corresponding to cold weather application, cold brine may be used to obtain a pipe temperature of 32 F. or even less.

After the pipe section is brought to the desired temperature, its temperature will tend to rise or fall due to transfer of heat between the pipe surface and the surrounding atmosphere unless the atmosphere is at the same temperature as the Compression springs 56 2,088,622 housing and the liquid contained therein. If the pipe is to be maintained at a temperature considerably above or below that of the surrounding atmosphere, it may be necessary to periodically drain some liquid from the section and replace it by hot or cold liquid to overcome the losses through such heat transfer. This same result can be obtained by continuously circulating liquid at the desired temperature through the housing.

The enamel or other bituminous composition is heated to approximately the desired temperature and a suitably regulated volume is introduced into the pct 30. The correct volume can readily be gauged by filling the pot each time to a predetermined mark. Cover 3| is then placed on the pot and the coating material therein is heated to the desired temperature by use of the ring-shaped gasburner surrounding the; pot.

When the coating material arrives at the proper,

temperature, as indicated by thermometer 33, crank 44 at the opposite end of the apparatus is turned causing chain 48 to pull the container and pot along the guides over the top of the pipe section at a uniform rate. As soon as the orifice in the apex of the pot slides past the springactuated plate, the enamel or other coating material will flow through the orifice onto the top of the pipe section below. The coating material will flow down the sides of the pipe and, in cooling will form a protective coating 58 thereon, as shown in Fig. 3.

When the coating has cooled and set sufficiently to be readily handled, it is removed from the non-adhesive oiled surface of the pipe and flattened out. In some cases the flattening operation can best be done by placing the coating on a fiat plate and putting both in an oven maintained at a slightly elevated temperature, care being taken to'avoid sticking or deformation of the sheet.

Thickness measurements of the coating are then made at selected points in the surface of the coating sheet using a suitable form of micrometer caliper. Preferably ten measurements are made corresponding to four on each side and two along the top of the pipe according to the original position of the coating on the pipe.

My apparatus and method for determining the flow characteristics of pipe coatings are of direct value in selecting commercial coatings, in determining their optimum application temperatures,

and in controlling field practice to secure coatings of the desired thickness. The results obtained by .the use of my apparatus correspond very closely to those obtained in practical .field application. Moreover, the apparatus is simple in design, easy to operate, and can be manufactured at a minimum cost.

mitting the coating material to spread" and solidify on said surface to form a solid layer thereon, removing the solid coating layer from the surface, measuring the thickness of the layer, and determining from the thickness of said layer as an index, the flowability of said coating material.

2. The method of determining the flowability of bituminous coating material which sets predetermined quantity of ,said coating material in liquid condition and at a predetermined temperature onto a curved surface while maintaining the surface at a predetermined temperature during the application of the coating material thereto, permitting the coating material to spread and solidify on said surface to form a solid coating layer, removing the solid coating layer from the surface, measuring the thickness of the coating layer, and determining from the thickness of said layer as an index, the flowability I of said coating material.

3. The method of determining the flowability of bituminous coating material which sets upon cooling, which comprises oiling a semi-cylindrical surface, progressively applying a measured quantity of the bituminous material in liquid condition and at a predetermined temperature onto ,the oiled surface while maintaining the surface at a predetermined temperature during the application of the coating material thereto, permitting the coating material to spread and solidify on this surface to form a solid semi-cylindrical coating layer, removing the solid semi-cylindrical coating layer from the surface, flattening the semi-cylindrical coating layer, measuring the thickness of the flattened coating layer at a plurality of points and determining from the average of said measurements as an index, the flowability of said bituminous coating material.

4. Apparatus for determining the flowability of coating materials comprising a container for holding coating material, means for heating the coating material and maintaining it at the desired temperature, a surface on which the heated l coating material is poured, and means for maintaining the surface at the desired temperature.

5. Apparatus for determining the pouring characteristics of coating materials, which comprises a container for holding coating materials and having an orifice in the bottom thereof, means for heating the coating material in the container and maintaining it at the desired temperature, means for moving the container longitudinally over a section of pipe, and means for automatically opening the orifice in the bottom of the container upon relative longitudinal movement of the container and pipe.

6. Apparatus for measuring the pouring char- I acteristics of coating materials, comprising a pot for holding coating material, means for heating the coating material in the pot to any desired temperature, a section of pipe underneath the pot, means for maintaining the pipe at any desired temperature, and means for discharging the coating material from the pot onto the pipe surface.

'7. Apparatus for measuring the flowability of pipe coating materials, comprising a pot for hold- .ing coating material positioned over a section. of

pipe and having an orifice in the bottom thereof, a vertically movable spring-actuated plate supported by the pipe for opening and closing the orifice upon relative movement of the pot and' pipe, and means for moving said pot longitudinally over the pipe section.

8; Apparatus for measuring the flowability of bituminous coating materials, comprising a housing, stationary guide bars extending longitudinally over said housing on either side thereof, a container supported by said'guide bars and movable therealong, a pot in said container for holding coating'material and having an orifice in the bottom thereof, means in said container upon cooling, which comprises applying a for heating the coating material, and a spring actuated plate supported by the housing for opening and closing the orifice in the pot upon relative movement of the housing and container.

9. Apparatus for measuring the flowability of bituminous coating materials, comprising a semicylindrical housing, means for maintaining the housing at the desired temperature, stationary guide bars extending longitudinally over said housing on either side thereof, a container sup- 10 ported. by said guide bars and movable therealong, a pot in said container for holding the coating material and having an orifice in the bottom thereof, a burner in said container -for heating the coating material in the pot to the desired temperature, and a vertically movable spring-actuated plate for opening and closing the orifice in the pot upon movement of the con tainer along the guide bars. 

